U.S. patent application number 11/058042 was filed with the patent office on 2005-09-01 for actuator device for a bicycle gearshift.
This patent application is currently assigned to Campagnolo, S.r.l.. Invention is credited to Meggiolan, Mario.
Application Number | 20050192140 11/058042 |
Document ID | / |
Family ID | 34746217 |
Filed Date | 2005-09-01 |
United States Patent
Application |
20050192140 |
Kind Code |
A1 |
Meggiolan, Mario |
September 1, 2005 |
Actuator device for a bicycle gearshift
Abstract
An actuator device for a bicycle gearshift is provided. The
actuator device having an articulated quadrilateral mechanism
intended to be integrally fixed to a bicycle frame and to a
derailleur of the gearshift, a motor member that acts on the
articulated quadrilateral mechanism to deform the articulated
quadrilateral, and displaces the derailleur and a support element
for the motor member associated with the articulated quadrilateral.
According to the invention, one of the motor member and the support
element comprises at least one jutting element and the other of the
motor member and the support element comprises at least one seat
adapted to receive said jutting element. Thus, the motor member is
associated with the support element so as to prevent mutual
translations in the axial direction in any operating or climatic
condition.
Inventors: |
Meggiolan, Mario; (Creazzo,
IT) |
Correspondence
Address: |
VOLPE AND KOENIG, P.C.
UNITED PLAZA, SUITE 1600
30 SOUTH 17TH STREET
PHILADELPHIA
PA
19103
US
|
Assignee: |
Campagnolo, S.r.l.
Vicenza
IT
|
Family ID: |
34746217 |
Appl. No.: |
11/058042 |
Filed: |
February 15, 2005 |
Current U.S.
Class: |
474/80 |
Current CPC
Class: |
B62M 25/08 20130101;
Y10T 403/7007 20150115; B62M 9/122 20130101 |
Class at
Publication: |
474/080 |
International
Class: |
F16H 009/00; F16H
059/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2004 |
EP |
04425126.2 |
Claims
What is claimed is:
1. Actuator device for a bicycle gearshift, comprising: an
articulated quadrilateral mechanism intended to be integrally fixed
to a bicycle frame and to a derailleur of the gearshift; a motor
member acting on said articulated quadrilateral mechanism to deform
the articulated quadrilateral thus determining the displacement of
said derailleur; a support element for said motor member associated
with the articulated quadrilateral; wherein one of said motor
member and said support element comprises at least one jutting
element and the other of said motor member and said support element
comprises at least one seat adapted to receive said at least one
jutting element.
2. Device according to claim 1, wherein said at least one jutting
element is defined on the outer surface of said motor member and
said at least one seat is defined on the inner surface of said
support element.
3. Device according to claim 1, wherein said at least one jutting
element is defined on the inner surface of said support element and
said at least one seat is defined on the outer surface of said
motor member.
4. Device according to claim 1, wherein said at least one jutting
element and said at least one seat define a bayonet coupling
between said motor member and said support element.
5. Device according to claim 1, wherein said at least one jutting
element is mounted through the interposition of an elastic
element.
6. Device according to claim 5, wherein said at least one jutting
element and said at least one seat define a snap coupling between
said motor member and said support element.
7. Device according to claim 1, wherein said at least one jutting
element comprises a substantially hemispherical surface.
8. Device according to claim 1, wherein said at least one seat
comprises a substantially cylindrical recess.
9. Device according to claim 1, wherein said at least one jutting
element and said at least one seat comprise respective prismatic
surfaces.
10. Device according to claim 1, wherein said at least one jutting
element is made of metallic material.
11. Device according to claim 1, wherein said support element
comprises at least one elastically yielding free end portion
provided with a pair of facing eyelets adapted to receive clamping
means of said support element around said motor member.
12. Device according to claim 1, wherein said support element is
pivotally associated with said articulated quadrilateral.
13. Device according to claim 12, wherein said articulated
quadrilateral mechanism comprises four connecting rods hinged
together along four pin axes by four pin elements, where a first
connecting rod is adapted to be integrally fixed to the bicycle
frame and a second connecting rod, opposite to the first connecting
rod in the articulated quadrilateral, is adapted to support the
derailleur of the gearshift, and wherein said motor member acts
between two opposite pin elements of the articulated quadrilateral
along a drive axis that substantially intersects the pin axis of
both of said two opposite pin elements and said support element is
associated with the second of said two opposite pin elements.
14. Device according to claim 1, wherein said support element is
integrally formed with said articulated quadrilateral.
15. Device according to claim 14, wherein said articulated
quadrilateral mechanism comprises four connecting rods hinged
together along four pin axes by four pin elements, where a first
connecting rod is adapted to be integrally fixed to the bicycle
frame and a second connecting rod, opposite to the first connecting
rod in the articulated quadrilateral, is adapted to support the
derailleur of the gearshift, and wherein said motor member acts
between said first connecting rod of the articulated quadrilateral
and an adjacent connecting rod through the operative interposition
of an actuation arm integrally associated with said adjacent
connecting rod and said support element is integrally formed with
said first connecting rod.
16. Device according to claim 15, wherein said support element
comprises at least one elastically yielding free end portion
provided with two facing eyelets adapted to receive clamping means
of said support element around said motor member and, at said at
least one elastically yielding free end portion, a first slit
arranged between said two eyelets and extending longitudinally
starting from a free end of said support element, wherein said seat
is defined at an end of said first slit opposite to said free end
of said support element.
17. Device according to claim 16, wherein said support element
comprises a second slit substantially transversal with respect to
said first slit and intersecting said first slit at said end of
said first slit opposite to said free end of said support element,
wherein said at least one seat is formed at the intersection of
said first and second slits.
18. Device according to claim 1, wherein said at least one seat has
a substantially closed configuration.
19. A motorized actuator for a bicycle gearshift comprising: an
articulating mechanism having a first portion connected to a
bicycle frame and a second portion connected to a derailleur; a
support mechanically coupled to the articulating mechanism; and a
motor seated within the support, the motor having a shaft rotatable
about an axis and that is operatively connected to the articulating
mechanism, wherein the motor and the support each comprises a
retaining element, the retaining elements being matingly engagable
and preventing axial translation of the motor when seated within
the support.
20. The actuator of claim 19, wherein one of the retaining elements
is a protuberance and the other is a recess.
21. The actuator of claim 20, wherein the motor comprises the
protuberance and the support comprises the recess.
22. The actuator of claim 20, wherein the support comprises the
protuberance and the motor comprises the recess.
23. The actuator of claim 20, wherein the protuberance has a shape
that is either hemispherical, prismatic or quadrangular.
24. The actuator of claim 19, wherein said shaft comprises a free
end having a threaded portion, said threaded portion engagable with
a portion of the articulating mechanism and causes the engaged
portion of the mechanism to travel along the threaded portion when
the shaft rotates resulting in a deformation of the articulating
mechanism and displacement of the derailleur.
25. The actuator of claim 19, wherein said articulating mechanism
comprises at least four connecting rods hingedly connected about at
least four pin axes by at least four pin elements wherein a first
connecting rod is fixable to a bicycle frame and a second
connecting rod, opposite the first connecting rod is fixable to the
derailleur of the gearshift and wherein said motor acts between a
third pin element and a fourth pin element along an axis that
substantially intersects a third axis and a fourth pin axis, and
said support is associated with said third pin element.
26. The actuator of claim 19, wherein the retaining elements define
a bayonet coupling between said motor and said support.
27. The actuator of claim 20, wherein said protuberance is mounted
through the interposition of an elastic element.
28. The actuator of claim 20, wherein said articulating mechanism
comprises four connecting rods hinged together along four pin axes
by four pin elements, where a first connecting rod is fixable to a
bicycle frame and a second connecting rod, opposite to the first
connecting rod in the articulating mechanism, is fixable to the
derailleur of the gearshift, and wherein said motor acts between
said first connecting rod of the articulating mechanism and an
adjacent connecting rod through the operative interposition of an
actuation arm integrally associated with said adjacent connecting
rod and said support element is integrally formed with said first
connecting rod.
29. The actuator of claim 28, wherein said support comprises at
least one elastically yielding free end portion provided with two
facing eyelets adapted to receive clamping means of said support
element around said motor member and, at said at least one
elastically yielding free end portion, a first slit arranged
between said two eyelets and extending longitudinally starting from
a free end of said support, wherein said seat is defined at an end
of said first slit opposite to said free end of said support.
30. The actuator of claim 29, wherein said support comprises a
second slit substantially transversal with respect to said first
slit and intersecting said first slit at said end of said first
slit opposite to said free end of said support element, wherein
said at least one recess is formed at the intersection of said
first and second slits.
31. An actuator for a bicycle gearshift comprising: an articulating
quadrilateral, having a first portion fixable to a bicycle frame
and a second portion fixable to a bicycle derailleur, said
quadrilateral deformable to displace said derailleur to effect a
gear change; a support mechanically coupled to said quadrilateral
and including at least one seat having a recess; and a motor
supported by the support connected to the quadrilateral via a shaft
that rotates about an axis and operatively connected to a power
supply, said motor further comprises at least one stop having a
protuberance disposed on an outer surface thereof matingly
engagable with said at least one seat to prevent axial translation
of the motor with respect to the support.
32. An actuator for a bicycle gearshift comprising: an articulating
quadrilateral, having a first portion fixable to a bicycle frame
and a second portion fixable to a bicycle derailleur, said
quadrilateral deformable to displace said derailleur to effect a
gear change; a support mechanically coupled to said quadrilateral
and including at least one seat having a protuberance; and a motor
supported by the support connected to the quadrilateral via a shaft
that rotates about an axis and operatively connected to a power
supply, said motor further comprises at least one stop having a
recess disposed on an outer surface thereof matingly engagable with
said at least one seat to prevent axial translation of the motor
with respect to the support.
33. An actuator for a bicycle gearshift comprising: an articulating
quadrilateral, having a first portion fixable to a bicycle frame
and a second portion fixable to a bicycle derailleur, said
quadrilateral deformable to displace said derailleur to effect a
gear change; a support mechanically coupled to said quadrilateral
and including at least one seat; and a motor supported by the
support connected to the quadrilateral via a shaft that rotates
about an axis and operatively connected to a power supply, said
motor further comprises at least one stop having a protuberance
disposed on an outer surface thereof matingly engagable with said
at least one seat to prevent axial translation of the motor with
respect to the support, wherein said shaft comprises a free end
having a threaded portion, said threaded portion engagable with a
portion of the articulating quadrilateral and causes the engaged
portion of the quadrilateral to travel along the threaded portion
when the shaft rotates resulting in a deformation of the
articulating quadrilateral and displacement of the derailleur.
34. An actuator for a bicycle gearshift comprising: an articulating
quadrilateral, having a first portion fixable to a bicycle frame
and a second portion fixable to a bicycle derailleur, said
quadrilateral deformable to displace said derailleur to effect a
gear change; a support mechanically coupled to said quadrilateral
and including at least one seat having a recess; and a motor
supported by the support connected to the quadrilateral via a shaft
that rotates about an axis and operatively connected to a power
supply, said motor further comprises at least one stop having a
protuberance disposed on an outer surface thereof matingly
engagable with said at least one seat to prevent axial translation
of the motor with respect to the support, wherein said articulating
quadrilateral comprises at least four connecting rods hingedly
connected about at least four pin axes by at least four pin
elements wherein a first connecting rod is fixable to a bicycle
frame and a second connecting rod, opposite the first connecting
rod is fixable to the derailleur of the gearshift and wherein said
motor acts between a third pin element and a fourth pin element
along an axis that substantially intersects a third axis and a
fourth pin axis, and said support is associated with said third pin
element.
35. An actuator for a bicycle gearshift comprising: an articulating
quadrilateral, having a first portion fixable to a bicycle frame
and a second portion fixable to a bicycle derailleur, said
quadrilateral deformable to displace said derailleur to effect a
gear change; a support mechanically coupled to said quadrilateral
and including at least one seat having a recess; and a motor
supported by the support connected to the quadrilateral via a shaft
that rotates about an axis and operatively connected to a power
supply, said motor further comprises at least one stop having a
protuberance disposed on an outer surface thereof matingly
engagable with said at least one seat to prevent axial translation
of the motor with respect to the support, wherein said articulating
quadrilateral comprises at least four connecting rods hingedly
connected about at least four pin axes by at least four pin
elements wherein a first connecting rod is fixable to a bicycle
frame and a second connecting rod, opposite the first connecting
rod is fixable to the derailleur of the gearshift and wherein said
motor acts between said first connecting rod of the articulated
quadrilateral and an adjacent connecting rod through the operative
interposition of an actuation arm integrally associated with said
adjacent connecting rod and said support is integrally formed with
said first connecting rod.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an actuator device for a
bicycle gearshift, that is to a mechanical device which causes the
displacement of the chain between different toothed wheels, by
displacing a derailleur by which the chain is guided.
BACKGROUND
[0002] Throughout the present description and the subsequent
claims, the gearshift to which reference is made can either be the
rear gearshift, which moves the chain between the different
sprockets associated with the rear wheel of the bicycle, and the
front gearshift, which moves the chain between the different crowns
or chain rings associated with the pedal cranks.
[0003] Usually, the actuator device of the gearshift comprises an
articulated quadrilateral mechanism intended to be integrally fixed
to the bicycle frame and to the derailleur of the gearshift; the
deformation of the articulated quadrilateral causes the
displacement of the derailleur thereby causing a gear shift.
[0004] The aforementioned deformation of the articulated
quadrilateral can be obtained manually, through the movement of
control levers transmitted to the actuator through cables of the
Bowden type, or else with an electric motor that--following an
appropriate command imparted by the cyclist and through a suitable
mechanism--displaces different parts of the articulated
quadrilateral with respect to each other, deforming it and thus
displacing the derailleur.
[0005] Devices of this type, and in particular actuated through an
electric motor, are known in the art.
[0006] The actuator devices of the prior art, although
substantially meeting the constant demands of gearshift producers
to improve the precision of actuation, upon which the ease and
reliability of operation of the gearshift depends, do, however,
have some drawbacks still not solved.
[0007] In particular, the Applicant has noted that in the above
mentioned actuator devices equipped with electric motors, the axial
component of the force applied by a drive shaft to the transmission
elements causes an equal and opposite axial thrust on the motor,
which, if not suitably countered, tends to make it move axially
with respect to the support element that houses the motor itself.
This effect is emphasized in certain hot or cold environmental
conditions, in which the different expansion coefficient of the
materials constituting the casing of the motor and the support
element further worsen the coupling between motor and support
element. An undesired translation in the axial direction of the
motor with respect to the support element causes a corresponding
translation of the drive shaft with respect to the transmission
elements, and therefore a worsening of the accuracy of actuation of
the derailleur. Undesired axial translations can also be caused by
accidental knocks on the gearshift.
[0008] The technical problem underlying the present invention is
therefore that of providing an actuator device for a bicycle
gearshift of the type described above, in which the coupling
between motor and support element is such as to prevent mutual
translations in the axial direction in any operating or climatic
condition.
SUMMARY
[0009] According to the present invention, such a problem is solved
by an actuator device for a bicycle gearshift comprising: an
articulated quadrilateral mechanism intended to be integrally fixed
to a bicycle frame and to a derailleur of the gearshift; a motor
member acting on said articulated quadrilateral mechanism to deform
the articulated quadrilateral thus determining the displacement of
said derailleur; a support element for said motor member associated
with the articulated quadrilateral; characterized in that one of
said motor member and said support element comprises at least one
jutting element or protuberance and the other of said motor member
and said support element comprises at least one seat adapted to
receive said at least one jutting element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Additional features and advantages of the present invention
shall become clearer from the following description of some
preferred embodiments thereof, given hereafter, for indicative and
not limitative purposes, with reference to the attached drawings.
In such drawings:
[0011] FIG. 1 is a perspective view with partially removed parts of
an actuator device for a bicycle gearshift according to a first
preferred embodiment of the invention;
[0012] FIG. 2 is an exploded perspective view of two details of the
actuator device of FIG. 1;
[0013] FIG. 3 is a perspective view of the details of FIG. 2 in an
assembled configuration;
[0014] FIG. 4 is a perspective view with partially removed parts of
an actuator device for a bicycle gearshift according to a second
preferred embodiment of the invention;
[0015] FIG. 5 is an exploded perspective view of two details of the
actuator device of FIG. 4;
[0016] FIG. 6 is a perspective view of the details of FIG. 5 in an
assembled configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS INTRODUCTION TO
THE EMBODIMENTS
[0017] Advantageously, when the motor member is associated with the
support element, the jutting element is housed in the
aforementioned seat; in such a configuration, any possible
translation in the axial direction of the motor member with respect
to the support element is prevented. Both at rest and during
operation, the motor member thus keeps the correct positioning with
respect to the support element and with respect to the remaining
transmission elements on which it acts, avoiding the drawbacks
mentioned above with reference to the prior art. Moreover, such a
result is achieved in a particularly simple manner from both the
manufacturing point of view and the operative point of view.
Indeed, the jutting element and the respective seat can be formed
on the motor member and on the support element through conventional
mechanical processing, at the time of manufacture or thereafter,
and the assembly/disassembly operations of the motor member are
quick and easy and do not require the use of specific tools.
[0018] Preferably, the jutting element is defined on the outer
surface of the motor member and the seat is defined on the inner
surface of the support element. Such an embodiment is advantageous
since it requires minimal interventions on the outer surface of the
motor, which is generally more fragile than the support
element.
[0019] In an alternative embodiment, that is less preferred but
still considered to be of interest, it is possible to define the
jutting element on the inner surface of the support element and the
seat on the outer surface of the motor member. The outer surface of
the motor could in such a case comprise, in addition to the seat
for the jutting element, appropriate recesses adapted to slidably
receive the jutting element towards or away from the seat during
the assembly or disassembly of the motor into and from the support
element.
[0020] Preferably, the jutting element and the seat define a
bayonet coupling between the motor member and the support element.
Such a type of coupling advantageously combines features of
simplicity, robustness and stability of coupling.
[0021] According to a second embodiment of the invention, the
jutting element is mounted on the outer surface of the motor member
through the interposition of an elastic element. In such a case the
jutting element, whilst still being able to firmly engage with the
seat when taken to it thanks to the action of the elastic element,
can advantageously retract or be retracted to ease sliding of the
motor member with respect to the support element during assembly
and disassembly of the motor member into and from the support
element.
[0022] In an alternative embodiment, it is equally possible to
mount, through the interposition of an elastic element, the jutting
element on the inner surface of the support element and to define
the seat on the outer surface of the motor member.
[0023] In the two embodiments just described above the jutting
element and the seat define a snap coupling between the motor
member and the support element. In such a type of coupling, the
seat preferably has a substantially closed configuration, i.e. it
houses the jutting element without any possibility of mutual
movement, apart from small displacements due to size tolerances.
Such a type of coupling is particularly advantageous since it
prevents both translations and mutual rotations between motor
member and support element, thus ensuring the maintenance of the
correct positioning of the motor member with respect to the support
element and to the remaining transmission elements on which the
motor member acts. Moreover, at a cost of a minimal complication
with respect to the mentioned bayonet coupling, it can
advantageously allow greater flexibility of positioning of the
jutting element and of the corresponding seat, since it is not
necessary to arrange, on the surface carrying the seat, possible
additional recesses adapted to slidably receive the jutting element
towards or away from it during assembly and disassembly of the
motor member into and from the support element.
[0024] Preferably, the jutting element comprises a substantially
hemispherical surface, in order to ease the sliding of the jutting
element towards or away from the seat and to ease its housing in
such a seat, at the same time limiting wear during such
operations.
[0025] Preferably, the seat comprises a substantially cylindrical
recess, which can be formed in a simple manner on the inner surface
of the support element (or alternatively on the outer surface of
the motor) even in a step subsequent to the manufacture, for
example through milling or punching.
[0026] In an alternative embodiment, the jutting element and the
seat comprise respective prismatic surfaces, in order to increase
the stability of the coupling between jutting element and seat.
[0027] Preferably, the jutting element is made from metallic
material; such a material is particularly suitable due to its
characteristics of resistance to stress and wear.
[0028] Preferably, the support element comprises at least one
elastically yielding free end portion provided with a pair of
facing eyelets adapted, to receive clamping means of said support
element of the motor member around said motor member. This provides
a further fastening system between motor member and support
element, in particular advantageous for preventing rotations of the
motor member with respect to the support element in the specific
case where the seat does not have a substantially closed
configuration.
[0029] The clamping means of the two eyelets are preferably of the
conventional type, for example a bolt. The support element can be
pivotally associated with the articulated quadrilateral or
integrally formed with the articulated quadrilateral.
[0030] In a first preferred embodiment of the actuator device of
the present invention, the articulated quadrilateral mechanism
comprises four connecting rods hinged together along four pin axes
by four pin elements, where a first connecting rod is adapted to be
integrally fixed to the bicycle frame and a second connecting rod,
opposite to the first connecting rod in the articulated
quadrilateral, is adapted to support the derailleur of the
gearshift, wherein the motor member acts between two opposite pin
elements of the articulated quadrilateral along a drive axis that
substantially intersects the pin axis of both of the aforementioned
two pin elements and the support element is associated with the
second of said two opposite pin elements.
[0031] Throughout the present description and the subsequent
claims, the term "connecting rod" is generically used to indicate a
rigid element suitable for transmitting the motion to other
elements to which it is pivotally connected.
[0032] This embodiment of the articulated quadrilateral mechanism
is particularly effective since the deformation action takes place
substantially along one of the diagonals of the articulated
quadrilateral; this ensures the best conditions for controlling the
deformation itself and thus for controlling the movement of the
second connecting rod with the derailleur.
[0033] In a second preferred embodiment of the actuator device of
the present invention, the motor member acts between said first
connecting rod of the articulated quadrilateral and an adjacent
connecting rod through the operative interposition of an actuation
arm integrally associated with said adjacent connecting rod and
preferably the support element of the motor member is integrally
formed with the first connecting rod.
[0034] Preferably, the support element comprises, at said at least
one first free end portion, a first slit arranged between the
aforementioned two facing eyelets and extending longitudinally
starting from a free end of said support element, wherein the seat
is defined at one end of said first slit opposite to said free end
of the support element.
[0035] Even more preferably, the support element comprises a second
substantially transversal slit intersecting said first slit at the
aforementioned end of the first slit opposite to said free end of
said support element, wherein the seat is formed at the
intersection of said first and second slits.
[0036] Preferably, in such a second embodiment of the actuator
device of the present invention, the seat has a substantially
closed configuration, where with the expression "substantially
closed" it is meant that the seat is perimetrically closed, apart
from small openings defined at the aforementioned slits, so as to
house the jutting element in a way that prevents both translations
and mutual rotations between motor member and support element.
DESCRIPTION OF THE EMBODIMENTS
[0037] In such figures an actuator device for a bicycle gearshift
in accordance with the present invention is generally indicated at
1. In all of the figures, structurally or functionally equivalent
elements are indicated with the same reference numerals. Both the
gearshift and the bicycle are not illustrated.
[0038] The actuator device 1 comprises an articulated quadrilateral
mechanism 10, including four connecting rods: a first connecting
rod 101 adapted to be integrally fixed to the bicycle frame, a
second connecting rod 102 opposite to the first connecting rod 101
in the articulated quadrilateral 10 and adapted to be fixed to a
support for the derailleur of the gearshift, a third connecting rod
103 and a fourth connecting rod 104. The connecting rods 101, 102,
103 and 104 are articulated with each other along four pin axes
111, 112, 113 and 114 by four respective pin elements 121, 122, 123
and 124, so as to form the articulated quadrilateral 10. In
particular, each of the pin elements 121 and 122 is defined by a
single pin extending along the respective pin axis 111 and 112,
whereas each of the pin elements 123 and 124 is defined by a
respective pair of opposite pins aligned along the respective pin
axis 113 and 114.
[0039] With reference to the embodiment illustrated in FIGS. 1-3,
the specific configuration of the articulated quadrilateral 10 and
of the constitutive elements has already been described and
illustrated in detail in U.S. Patent Publication No. U.S.
2004014541, assigned to the same Assignee of the present invention,
which is incorporated herein by reference. Such an embodiment is
particularly suitable for use in a rear gearshift.
[0040] In such an embodiment, the actuator device 1 comprises a
motor member 2, typically an electric motor, which is associated
with the pin element 123 and acts between the pin element 123 and
the opposite pin element 124 along a drive axis X-X; such an axis
substantially intersects the pin axes 113 and 114, or rather
substantially coincides with the diagonal of the articulated
quadrilateral 10 passing through the aforementioned pin axes 113
and 114.
[0041] The motor member 2 is provided with a drive shaft 3. At the
free end of the drive shaft 3 a screw 4 is integrally formed. This
screw is adapted to engage a nut screw (not shown in the figures
but disclosed in Applicant's pending U.S. patent application Ser.
No. 10/911,195 which is incorporated herein by reference) integral
with the pin element 124. The rotation of the drive shaft 3, and
therefore of the screw 4, causes the sliding of the nut screw on
the screw 4 and, consequently, a variation in the distance,
measured along the drive axis X-X, between the motor member 2 fixed
to the pin element 123 and the nut screw fixed to the opposite pin
element 124. Such a variation in turn causes a corresponding
deformation of the articulated quadrilateral 10 and, therefore, the
displacement of the derailleur associated with it.
[0042] The motor member 2 is structurally associated with the pin
element 123 by means of a support element 5, which is integrally
associated with the first pin element 123. The support element 5
and the motor member 2 are also preferably arranged in a space 11
inside the articulated quadrilateral 10, in order to minimize the
overall size of the actuator device 1.
[0043] As shown more precisely in FIGS. 2 and 3, the support
element 5 is formed by an open-cradle monolithic structure,
preferably made of plastic material, with two side walls 51 and 52
connected by a bridge 53 and having an elastically yielding free
end portion 5a. At such a free end portion 5a of the support
element 5, the two side walls 51 and 52 are provided with
respective facing eyelets 54 and 55 that are aligned so as to be
able to receive conventional clamping means, like for example a
bolt 57 (FIG. 1). Between the walls 51, 52 a receiving space 56 is
defined for the motor member 2.
[0044] Between the two eyelets 54, 55 a space 58 is defined that
ensures the possibility of carrying out a clamping of the support
element 5 around the motor member 2.
[0045] According to the invention, a jutting element or
protuberance 8 is defined on the outer surface of the motor member
2 and at an end thereof; a corresponding seat 6, adapted to receive
the jutting element 8, is defined on the inner surface of the
support element 5. The jutting element 8 comprises a preferably
metallic substantially hemispherical surface and preferably is
integrally formed on the outer surface of the motor member 2;
alternatively, it can be fixed onto said surface mechanically or
through welding or other conventional mechanical processes.
[0046] The seat 6 comprises a substantially cylindrical recess 7,
with substantially the same diameter as that of the hemispherical
surface of the jutting element 8, so as to avoid undesired
clearances. The recess 7 extends on the inner surface of the
support element 5 along a direction substantially perpendicular to
the drive axis X-X and up to an edge of the side wall 52 so as to
be able to engage/disengage the jutting element 8 with respect to
the seat 6.
[0047] In the embodiment shown in FIGS. 1, 2 and 3 the jutting
element 8 and the seat 6 define a bayonet coupling between the
motor member 2 and the support element 5. To carry out assembly,
the motor member 2 is at first axially introduced into the
receiving space 56 as indicated by the arrow A of FIG. 2; when the
jutting element 8 is at the recess 7 the motor member 2 is rotated
according to the arrow B of FIG. 3 until the jutting element 8
engages completely with the seat 6. In this condition, shown in
FIG. 1, axial displacements of the motor member 2 with respect to
the support element 5 are substantially prevented; possible
rotations, on the other hand, are substantially prevented by the
clamping around the motor member 2 of the eyelets 54 and 55 through
conventional clamping means, like for example bolts 57.
[0048] Alternatively, the jutting element 8 can be defined on the
inner surface of the support element 5, whereas the seat 6 is
defined on the outer surface of the motor member 2. In this case,
the seat 6 can be configured in such a way as to define a
substantially L-shaped path for the jutting element 8, with a first
portion substantially parallel to the drive axis X-X, adapted to
slidably receive the jutting element 8 when the motor member 2 is
introduced into the receiving space 56 of the support element 5,
and a second portion substantially transversal with respect to the
axis X-X, adapted to house the jutting element 8 and axially lock,
through rotation about the axis X-X, the motor member 2 in the
support element 5.
[0049] The jutting element 8 can also be mounted on the outer
surface of the motor element 2 or on the inner surface of the
support element 5 through the interposition of an elastic element.
In such a way the jutting element 8 and the seat 6 allow a snap
coupling to be realized between the motor element 2 and the support
element 5.
[0050] FIGS. 4, 5 and 6 show a further embodiment of an actuator
device according to the invention, particularly suitable for a
derailleur for a front gearshift. Also in this case, the actuator
device 1 comprises an articulated quadrilateral mechanism 10
including the four connecting rods 101, 102, 103 and 104, connected
together through the four pin elements 121, 122, 123 and 124. The
connecting rod 101 is adapted to be integrally fixed to the bicycle
frame, whereas the connecting rod 102 substantially coincides
structurally with the derailleur. Also in this case, each of the
pin elements 121 and 122 is defined by a single pin extending along
the respective pin axis 111 and 112, whereas each of the pin
elements 123 and 124 is defined by a respective pair of opposite
pins aligned along the respective pin axis 113 and 114.
[0051] The actuator device 1 further comprises a motor member 2,
typically an electric motor, which is structurally associated with
the connecting rod 101 and acts between the connecting rod 101 and
the adjacent connecting rod 103 through the interposition of an
actuation arm 12 integrally formed with the connecting rod 103. The
motor member 2 moves in rotation a worm screw 14, which engages a
toothed sector 13 formed on the actuation arm 12 (FIG. 4). The
consequent movement of the connecting rod 103 around the pin
element 123 determines a deformation of the articulated
quadrilateral 10 and the displacement of the derailleur.
[0052] The specific configuration of the articulated quadrilateral
10 and of the constitutive elements, as well as the different
embodiments of the gear transmission between the connecting rod 101
and the adjacent connecting rod 103, have already been illustrated
in detail in U.S. Pat. No. 6,679,797 to the same Assignee of the
present invention and is incorporated herein by reference.
[0053] The motor member 2 is structurally associated with the
connecting rod 101 by means of a support element 5 integrally
formed at an end of the connecting rod 101.
[0054] As shown more precisely in FIGS. 5 and 6, the support
element 5 comprises a substantially cylindrical receiving space 56
for the motor member 2. At an elastically yielding free end portion
5a of the support element 5 eyelets 54 and 55 are defined facing
each other and aligned so as to be able to receive conventional
clamping means, like for example a bolt 57 (FIG. 4). The support
element 5 further comprises a first slit 15 that extends
longitudinally starting from a free end of the support element 5
and a second slit 16, that is substantially transversal to and
intersects the first slit 15 at an end thereof opposite to the
aforementioned free end of the support element 5. The first slit 15
longitudinally separates the eyelets 54 and 55 and ensures the
possibility of carrying out a clamping of the eyelets 54 and 55
around the motor member 2 to prevent possible rotations between
motor member 2 and support element 5.
[0055] Also in this embodiment, a jutting element 8 is defined on
the outer surface of the motor member 2 and at an end thereof. The
jutting element comprises a preferably metallic and substantially
hemispherical surface, preferably formed integrally on the outer
surface of the motor member 2. Alternatively, the jutting element 8
can be fixed on said surface mechanically or through welding. The
support element 5 comprises a corresponding seat 6 formed at the
intersection of the longitudinal slit 15 and the transversal slit
16.
[0056] For assembly the motor member 2 is at first axially
introduced in the receiving space 56 as indicated by the arrow A of
FIG. 5 making the jutting element 8 slide in the longitudinal slit
15 until it is at the seat 6 (FIG. 6). The entry and the sliding of
the jutting element 8 in the longitudinal slit 15 is obtained
thanks to the elastic yield of the end portion 5a of the support
element 5. Thereafter the eyelets 54 and 55 are clamped through the
bolt 57 so as to ensure the simultaneous clamping around the motor
member 2 and the keeping of the jutting element 8 inside the seat
6. In this condition, shown in FIG. 4, both axial displacements and
rotations of the motor member 2 with respect to the support element
5 are substantially prevented.
[0057] Advantageously, when the motor member is associated with the
support element, the jutting element is housed in the
aforementioned seat; in such a configuration, any possible
translation in the axial direction of the motor member with respect
to the support element is prevented. Both at rest and during
operation, the motor member thus keeps the correct positioning with
respect to the support element and with respect to the remaining
transmission elements on which it acts, avoiding the drawbacks
mentioned above with reference to the prior art. Moreover, such a
result is achieved in a particularly simple manner both from the
manufacturing point of view and the operative point of view.
Indeed, the jutting element and the respective seat can be formed
on the motor member and on the support element through conventional
mechanical processing, at the time of manufacture or thereafter,
and the assembly/disassembly operations of the motor member are
quick and easy and do not require the use of specific tools.
[0058] Preferably, the jutting element is defined on the outer
surface of the motor member and the seat is defined on the inner
surface of the support element. Such an embodiment is advantageous
since it requires minimal interventions on the outer surface of the
motor, which is generally more fragile than to the support
element.
[0059] Obviously, one skilled in the art may introduce
modifications and variants to the preferred embodiments of the
invention described above in order to satisfy specific and
contingent operational requirements, said modifications and
variants in any case falling within the scope of protection as
defined by the subsequent claims. For example, the jutting element
8 and the seat 6 may comprise respective prismatic surfaces, for
example quadrangular, in order to increase the stability of the
coupling between jutting element and seat.
* * * * *